Down-fired burner with a perforated flame holder

Patent metadata

Field	Value
Publication number	US-10088154-B2
Application number	US-201615235479-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Feb 14, 2014
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A down-fired flame burner includes a flame holder positioned below the burner. The flame holder includes a plurality of perforations that collectively confine a combustion reaction of the burner to the flame holder.

First claim

What is claimed is:

1. A down-fired burner comprising:
a down-fired fuel nozzle configured to output fuel in a downward direction;
an oxidant source configured to output an oxidant; and
a flame holder positioned below the down-fired fuel nozzle, the flame holder including:
an input surface facing the down-fired fuel nozzle;
an output surface opposite the fuel nozzle; and
a plurality of perforations extending from the input surface to the output surface and collectively configured to promote a combustion reaction of the fuel and oxidant within the perforations, wherein the flame holder is a refractory material.

2. The down-fired burner of claim 1 , wherein the flame holder is configured to contain a majority of the combustion reaction within the perforations.

3. The down-fired burner of claim 1 , wherein the flame holder is configured to contain 80% or more of the combustion reaction within the perforations.

4. The down-fired burner of claim 1 , wherein the flame holder is an integral structure.

5. The down-fired burner of claim 1 , wherein the flame holder is configured to initiate the combustion reaction.

6. A down-fired burner, comprising:
a down-fired fuel nozzle configured to output fuel in a downward direction;
an oxidant source configured to output an oxidant;
a flame holder positioned below the down-fired fuel nozzle, the flame holder including:
an input surface facing the down-fired fuel nozzle;
an output surface opposite the fuel nozzle; and
a plurality of perforations extending from the input surface to the output surface and collectively configured to promote a combustion reaction of the fuel and oxidant within the perforations; and

a preheating mechanism configured to heat the flame holder prior to starting the combustion reaction.

7. The down-fired burner of claim 6 , wherein the preheating mechanism comprises a second fuel nozzle configured to generate a flame adjacent to the flame holder.

8. The down-fired burner of claim 6 , wherein the preheating mechanism comprises a laser configured to irradiate the flame holder.

9. The down-fired burner of claim 6 , wherein the down-fired fuel nozzle is an adjustable nozzle and the preheating mechanism is configured to move the fuel nozzle closer to the flame holder during a preheating period and to retract the fuel nozzle after the preheating period.

10. The down-fired burner of claim 6 , comprising:
a temperature sensor configured to measure a temperature of the flame holder; and
a control circuit coupled to the temperature sensor, the fuel nozzle, and the preheating mechanism and configured to cause the fuel nozzle to output the fuel when the temperature of the flame holder is above a threshold temperature.

11. The down-fired burner of claim 10 , wherein the threshold temperature corresponds to a combustion temperature at which the flame holder can initiate combustion of the fuel within the perforations.

12. The down-fired burner of claim 6 , comprising a control circuit coupled to the preheating mechanism and the fuel nozzle and configured to initiate the fuel nozzle after the preheating mechanism has operated for longer than a threshold time.

13. The down-fired burner of claim 6 , wherein the preheating mechanism includes an electrical resistor coupled to the flame holder, the preheating mechanism being configured to heat the flame holder by passing a current through the electrical resistor.

14. A down-fired burner, comprising:
a down-fired fuel nozzle configured to output fuel in a downward direction;
an oxidant source configured to output an oxidant;
a flame holder positioned below the down-fired fuel nozzle, the flame holder including:
an input surface facing the down-fired fuel nozzle;
an output surface opposite the fuel nozzle; and
a plurality of perforations extending from the input surface to the output surface and collectively configured to promote a combustion reaction of the fuel and oxidant within the perforations; and

a tube extending vertically adjacent to the flame holder and containing a catalyst.

15. The down-fired burner of claim 14 , wherein the flame holder is configured to heat the tube and cause a reaction between the catalyst and a reactant in the tube.

16. The down-fired burner of claim 14 , wherein the tube comprises:
a first vertical portion;
a second vertical portion; and
a connecting portion connecting the first vertical portion to the second vertical portion such that the tube is substantially in a U shape.

17. The down-fired burner of claim 16 , wherein the tube comprises:
an input configured to pass reactant into the first vertical portion; and
an output configured to pass from the second vertical portion a reaction product of the reactant and the catalyst.

18. The down-fired burner of claim 16 , wherein the flame holder is positioned between the first and second vertical portions of the tube.

19. The down-fired burner of claim 1 , wherein the perforations are isolated from each other by a body of the flame holder.

20. The down-fired burner of claim 1 , wherein the input and output surfaces of the flame holder are substantially rectangular.

21. The down-fired burner of claim 1 , wherein the input and output surfaces of the flame holder are circular, elliptical, or ovular.

22. The down-fired burner of claim 1 , wherein a width of the flame holder in a horizontal direction is more than twice as large as a thickness of the flame holder in a vertical direction.

23. A method comprising:
heating a flame holder positioned within a combustion volume and having a plurality of perforations each extending from a top surface of the flame holder to a bottom surface of the flame holder, wherein the flame holder is of a refractory material;
outputting fuel from a first nozzle in a downward direction onto a top surface of the flame holder;
introducing an oxidant into the combustion volume;
igniting a combustion reaction of the fuel and oxidant in the plurality of perforations; and
containing the combustion reaction of the fuel and oxidant substantially in the perforations in the flame holder.

24. The method of claim 23 , comprising:
measuring a temperature of the flame holder; and
outputting the fuel onto the flame holder after the temperature of the flame holder has reached a threshold temperature.

25. The method of claim 24 , wherein the threshold temperature is a temperature at which the flame holder will ignite the combustion reaction within the perforations.

26. The method of claim 23 , wherein heating the flame holder comprises applying heat to the flame holder by a preheating mechanism positioned adjacent to the flame holder.

27. The method of claim 23 , comprising heating the flame holder by irradiating the flame holder with a laser.

28. The method of claim 23 , comprising heating the flame holder with a second fuel nozzle positioned adjacent to the flame holder.

29. The method of claim 23 , comprising heating the flame holder by passing a current through an electrical resistor coupled to the flame holder.

30. A method, comprising:
heating a flame holder positioned within a combustion volume and having a plurality of perforations each extending from a top surface of the flame holder to a bottom surface of the flame holder;
outputting fuel from a first nozzle in a downward directio

Assignees

• Clearsign Comb Corp

Inventors

• Colannino Joseph
• Karkow Douglas W
• Krichtafovitch Igor A
• Wiklof Christopher A

Classifications

• F23D14/70

  Baffles or like flow-disturbing devices · CPC title

• F23D14/30

  Inverted burners, e.g. for illumination · CPC title

• F23D11/406

  Flame stabilising means, e.g. flame holders · CPC title

• F23C99/006 Primary

  Flameless combustion stabilised within a bed of porous heat-resistant material (F23C13/00 takes precedence; gas burners with radiant combustion on a porous surface F23D14/16) · CPC title

• C01B2203/0816

  Heating by flames · CPC title